ogn arduino sensor

do.ino

void setup()
{
 Serial.begin(9600);
 analogReference(INTERNAL);
 delay(10);  // wait a sec for the analog reference to stabilize
}

void loop()
{
 Serial.print(averageTemperature()); // so we can debug
 Serial.print(' ');

  analogRead(A4);
  float v = analogRead(A4);
  v /= 751;
  v *= 4.6;

  Serial.println(v); // so we can debug
  delay(1000);
}

int readTemperature()
{
 ADCSRA |= _BV(ADSC); // start the conversion
 while (bit_is_set(ADCSRA, ADSC)); // ADSC is cleared when the conversion finishes
 return (ADCL | (ADCH << 8)) - 342; // combine bytes & correct for temp offset (approximate)}
}

float averageTemperature()
{
 ADMUX = 0xC8;
 readTemperature(); // discard first sample (never hurts to be safe)

 float averageTemp; // create a float to hold running average
 for (int i = 1; i < 1000; i++) // start at 1 so we dont divide by 0
   averageTemp += ((readTemperature() - averageTemp)/(float)i); // get next sample, calculate running average

 return averageTemp; // return average temperature reading
}